Breathing difficulties

Breathing difficulties (Shortness of breath/Dyspnea): When it is dangerous

Shortness of breath, or dyspnea, is a subjective feeling of insufficient air and difficulty breathing. It is one of the most alarming symptoms that can indicate serious heart or lung disease and often requires immediate medical attention. It is important to distinguish physiological shortness of breath (e.g., after intense physical exertion or during pregnancy, as described in the article "Shortness of breath during pregnancy") from pathological shortness of breath, which occurs with minimal exertion or at rest.

Respiratory system-related causes

Lung and airway diseases are the most common cause of shortness of breath.

• Obstructive diseases (difficulty exhaling):
  • Bronchial asthma: An attack causes bronchial spasm and swelling, accompanied by wheezing.
  • Chronic obstructive pulmonary disease (COPD): Chronic bronchitis and emphysema, usually in smokers.
  • Foreign body aspiration.
• Restrictive diseases (difficulty inhaling):
  • Pneumonia: Inflammation and fluid filling of the alveoli reduces the lung’s gas‑exchange surface.
  • Pneumothorax: Air enters the pleural cavity, causing lung collapse.

Cardiovascular causes

Shortness of breath is a key symptom of heart failure. When the heart cannot pump blood effectively, blood backs up in the pulmonary vessels, and fluid begins to seep into the alveoli (pulmonary edema), impairing normal gas exchange.

Other causes

• Anemia: Reduced hemoglobin leads to tissue oxygen starvation.
• Panic attack: Hyperventilation causes a sensation of air shortage.

Signs of respiratory failure in children are described in detail in the article "Breathing difficulties in children".